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Rear Brake Piston Retraction Problem

MagicMK

Drag Racing Champion
Location
PA
Okay, I have a 2008 GTI, and I'm using a HF brake retraction tool. The emergency brake is off (and even disconnected cable). After a few hours of messing around, I FINALLY was able to get the driver side rear brake piston fully retracted (using tool to screw clockwise, of course)... I ended up bleeding some fluid out of it in hopes that might help. After loosening the bleeder valve and draining some fluid from the caliper, I was able to retract enough to fit my brand new Bosch pads and Zimmerman rotor.

The problem I'm having now is the same damn thing is occurring on the passenger side (not to mention the friggin' set screw gulled and ended up pulling the entire hub with rotor attached -- I had a new hub). So, everything is done on this brake job, except I STILL can't get the passenger side rear brake piston to fully retract. As an aside, this is the second time I've done this job, and do not recall having anywhere near this many problems the last time I swapped the rotors and pads.

Any help would be greatly appreciated (inspection is overdue and I really need to get this done).

Thanks!
 

MagicMK

Drag Racing Champion
Location
PA
Ugh, really thought with all the posts on the GolfMKV.com forum that I might find somebody that addressed this problem, before. I guess I'll figure out on my own, one way or the other.
 

GTI's

Drag Racing Champion
Location
MD
I have not had it happen on a MK5 yet but on other VWs I have had them not go back in and needed to replace the caliper.
 

MagicMK

Drag Racing Champion
Location
PA
I have not had it happen on a MK5 yet but on other VWs I have had them not go back in and needed to replace the caliper.

Thanks, man... yeah, I'm hoping to avoid that, especially since it only has 87K miles on the car and the other caliper had the very same issue. It seems to me like there is a technique to get the piston to totally retract... but was wondering if anyone was able to get the piston retracted using a certain technique. If the caliper is threaded, why would it not retract when I'm using a tool that SHOULD thread it back into the caliper? I was hoping that somebody on this forum had some success... I'm guessing that there had to be a bunch of others that had similar problems.

As an aside, if you know of anyone else that has posted on this same issue in the past, then please let me know.

Thanks.
 

MagicMK

Drag Racing Champion
Location
PA
So, I ended up figuring this out, myself. I'll post it here to hopefully help somebody else that runs into the same problem, as this entire forum really doesn't discuss this issue much.

First, I figured out my problem was that I did not have constant pressure on HF piston retraction tool, but part of the reason I figured this out was the damn tool itself. The compression tool has a threaded rod with an end that accepts attachments. This end inserts into the the threaded screw/rod. In order to prevent the end from spinning, there appeared (at one time) to be some type of pin that was inserted into the threaded screw/rod and it ran through the extension insert. Mine was missing for some reason, and this allowed the end to spin... UNLESS you inserted something in it. So, I inserted a cotter pin in the hole, but the cotter pin blocked the the screw that attached to the backer plate... SO, when I went to insert the backer plate into the caliper to retract the piston, it would not fit. The reason it would not fit is because the cotter pin was STOPPING the bolt that holds the backer plate from going past the cotter pin in the hole.

I know this may be very confusing unless you've done this, before, but I've read of at least one other case where this happened to somebody else. It's a really friggin' odd design... why isn't the end permanently affixed to the threaded screw like the rounded end on a C Clamp? Because the backer plate would not fit inside the caliper (given how far the piston had extended), I tried to press the compression tool in by hand... and that DID NOT WORK! I ended up cutting a very small piece of the cotter pin off and then threading the backing plate OVER the thin piece of cotter pin. This allowed me FINALLY to have enough room to insert the backing plate in the caliper and then the compression tool worked like a charm. I had the piston fully retracted in about 2 minutes.

Ugh!!! I wasted hours figuring this out, but in the end, the issue was that my compression tool was not working properly due to this stupid effing pin that holds the round end piece onto the threaded screw. Once I jerry rigged this to work, I was finally able to properly engage the compression tool and it worked like a charm.

I will be taking this tool back to Harbor Freight to see if I can have it exchanged for another tool that has the end properly locked into the threaded screw. Hopefully this long explanation might help somebody else that runs into this same problem.
 

GTI's

Drag Racing Champion
Location
MD
Glad you figured it out, sound like you are describing a missing roll pin??

 

MagicMK

Drag Racing Champion
Location
PA
Glad you figured it out, sound like you are describing a missing roll pin??

YES! Thank you... didn't know the name, but that "pin" is exactly what I had imagined must have been in there at one time. I wasted hours trying to retract the very extended piston by hand (extended so far due to my surprisingly worn rear brake pads).

At any rate, when I was trying to Google the problem online, I believe I found at least one other person that was mystified about why their brake piston retraction tool's round metal end just kept spinning! I'm assuming HF will honor the warranty on the entire kit, but I will report back after I visit my local Harbor Freight.
 

MagicMK

Drag Racing Champion
Location
PA
Just as an FYI to anyone that purchase a Harbor Freight brake retraction kit (which now sells under the Maddox brand) retails for a rather pricey $50 for a 13 piece kit. HF manager told me my kit (which I believe was sold under "Pittsburgh" brand) would not have carried more than a 6 month warranty. My kit is probably about 7 - 10 years old, btw.

I purchased some rolling pins from HF for $4 with coupon, and just decided to buy a brand new 24 piece kit, with case, I found on Amazon, with a clockwise and counter clockwise retractor for only $21.19... which is about half of HF's 13 piece Maddox Kit, even with a 20% coupon (about $40). Just an FYI.
 

MagicMK

Drag Racing Champion
Location
PA
Hm, my tool is fixed in position as only Audi/Vw piston twister. Some Chinese ebay shit, but fits & works so IDGAF

Yeah, most of these tools come with adapters, but 95% of them are no-name Chinese tools. OTC and Snap-On sell versions, but, it's a bit hard to justify the price difference unless you're a professional... and even THEN, it's still a question whether they're worth the premium. I must admit, though, the HF price of $50 for a 13 piece kit kinda shocked me... esp when you compare it to the Amazon (best seller) kit I purchased for $21 with almost twice the number of parts.
 

golfballer78

Ready to race!
Location
southbay CA.
Car(s)
08' R32 dsg
Yeah, most of these tools come with adapters, but 95% of them are no-name Chinese tools. OTC and Snap-On sell versions, but, it's a bit hard to justify the price difference unless you're a professional... and even THEN, it's still a question whether they're worth the premium. I must admit, though, the HF price of $50 for a 13 piece kit kinda shocked me... esp when you compare it to the Amazon (best seller) kit I purchased for $21 with almost twice the number of parts.

Why do you need 13 piece kit unless it’s fpr a bunch of side jobs on other makes?
 
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